New Bicyclic Dioxanes, Their Preparation and Their Use as Fragrant Compounds

ABSTRACT

The invention is directed to the use of compounds of formula (I), as fragrant agents. In this formula: —R 3  and R 4  are independently a hydrogen atom, a C1-C6 alkyl group or a C2-C6 alkenyl group, R 5  is a C1-C6 alkyl group, a C2-C6 alkenyl group or a (CH2) 0-2 -aryl group, R 6  is a C1-C6 alkyl group, a C2-C6 alkenyl group, a (CH2) 0-2 -aryl group or a C5-C6 cycloalkyl or cycloalkenyl group, and R 7  is a hydrogen atom, a C1-C6 alkyl group or a C2-C6 alkenyl group; or R 3 , R 4  and R 5  are as above defined, and R 6  and R 7  together with the carbon atom to which they are attached form a C5-C6 cycloalkyl or cycloalkenyl group.

FIELD OF THE INVENTION

The invention relates to the field of fragrances. More particularly, the invention relates to bicyclic dioxanes, their method of preparation, and their use in the fields of perfumery.

BACKGROUND

Acetals form an important class of compounds in the field of aromatic chemistry, especially for use in basic media. The most important acetals are cyclic and are known for their fruity, floral or ambery fragrance (Kraft, P., Bajgrowicz, J. A., Angew. Chem. Int. Ed. 2000, 39, 2980-3010).

In the fruity notes, examples of commercially available acetals comprise Methyl Pamplemousse® (1), Floropal® (2), and Oxane® (3). These compounds are widely used in the field of perfumery. In the floral notes, rosy notes are quite important. One example of a cyclic dioxane having a floral note is Magnolan®. It is interestingly used to bring freshness, in particular to lily of the valley accords. Examples of cyclic dioxanes having ambery notes include Okoumal (6), Karanal (5), and Spirambrene (7). Okoumal possesses a powerful ambery fragrance which blends very well to woody accords. Karanal and Spirambrene also have a tenacious odour.

Problem to be Solved

The need for new compounds is of great importance for the development of the fragrance industry, which recently had to face stricter international regulatory requirements about the use of certain materials, as well as environmental concerns and customer demands for improved performance. Moreover, a phenomenon that is more and more frequently observed in the fields of perfumery are allergies to fragrant compounds. One way of minimizing the risk of allergies is regularly replacing fragrant compounds in perfumes. There is thus a constant need for new fragrant compounds that may be used to replace existing ones due to their similar fragrance.

Providing new fragrant compounds as well as means of selectively manufacturing such compounds is therefore an object of the invention.

The Applicant thus focused on the synthesis of new bicyclic acetals, more precisely bicyclic 1,3-dioxanes. Surprisingly and unexpectedly, the new 1,3-dioxane derivatives did not present the expected ambery notes, but mainly unexpected green notes.

SUMMARY OF THE INVENTION

The invention is directed to the use of compounds of formula:

as fragrant agents. In this formula:

-   -   R³ and R⁴ are independently a hydrogen atom, a C1-C6 alkyl group         or a C2-C6 alkenyl group,     -   R⁵ is a C1-C6 alkyl group, a C2-C6 alkenyl group or a         (CH₂)₀₋₂-aryl group,

R⁶ is a C1-C6 alkyl group, a C2-C6 alkenyl group, a (CH₂)₀₋₂-aryl group or a C5-C6 cycloalkyl or cycloalkenyl group, and

-   -   R⁷ is a hydrogen atom, a C1-C6 alkyl group or a C2-C6 alkenyl         group;         or     -   R³, R⁴ and R⁵ are as above defined, and     -   R⁶ and R⁷ together with the carbon atom to which they are         attached form a C₅-C₆ cycloalkyl or cycloalkenyl group.

Among the compounds defined by the formula (I) and used according to the invention as fragrant agents, to the inventors' knowledge, some are novel. In this context, the invention is also directed to compounds of formula (I), as defined above, with the proviso that said compound are not:

-   2,2-dimethyl-4-ethylhexahydrobenzo[1,3]dioxine -   2,2-dimethyl-4-n-penthylhexahydrobenzo[1,3]dioxine -   2,2-dimethyl-4-phenylhexahydrobenzo[1,3]dioxine -   2,4-dimethylhexahydrobenzo[1,3]dioxine -   2,4-diphenylhexahydrobenzo[1,3]dioxine -   4-ethyl-2-methylhexahydrobenzo[1,3]dioxine -   4-methyl-2-phenylhexahydrobenzo[1,3]dioxine -   2,2,4-trimethylhexahydrobenzo[1,3]dioxine.

This invention relates to the compounds of formula (I), as described above, as well as to any of their various stereoisomers.

The invention is also directed to a method of preparation of compounds of formula (I) as defined above.

DETAILED DESCRIPTION OF THE INVENTION

As set forth above, the invention is directed to compounds of formula:

as previously defined, and to the use of this type of compounds as fragrant agents.

Preferably, R³ and R⁴ are independently selected from the group consisting of a hydrogen atom, methyl, ethyl, i-propyl, i-butyl, and t-butyl, more preferably from the group consisting of a hydrogen atom, methyl and t-butyl.

R⁵ is preferably selected from the group consisting of methyl, ethyl, i-propyl, i-butyl, t-butyl, n-pentyl, 1-propen-1-yl, allyl, vinyl, and phenyl, more preferably from the group consisting of methyl, ethyl, i-butyl and phenyl.

R⁶ is preferably selected from the group consisting of methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, n-pentyl, 1-propen-1-yl, phenyl, benzyl and 2,4-dimethylcyclohexen-3-yl, more preferably from the group consisting of methyl, ethyl, i-propyl, n-pentyl, 1-propen-1-yl, phenyl, benzyl and 2,4-dimethylcyclohexen-3-yl. R⁷ is then preferably selected from the group consisting of a hydrogen atom, methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, n-pentyl and 1-propen-1-yl, more preferably from the group consisting of hydrogen atom, methyl and n-butyl.

Alternatively, R⁶ and R⁷, together with the carbon atom to which they are attached form a cyclopentyl or cyclohexyl group, preferably a cyclopentyl group.

According to a first preferred embodiment, R³ and R⁴ are hydrogen atoms. In this first embodiment, advantageously:

-   -   R⁵ is selected from the group consisting of methyl, ethyl,         i-butyl and phenyl, and more preferably methyl,     -   R⁶ is selected from the group consisting of methyl, ethyl,         i-propyl, phenyl, benzyl and 2,4-dimethylcyclohexen-3-yl, and         more preferably ethyl or benzyl,     -   R⁷ is selected from the group consisting of a hydrogen atom,         methyl and n-butyl, and more preferably a hydrogen atom.

According to a second preferred embodiment, R³ and R⁷ are hydrogen atoms, and R⁴ is t-butyl. In this second embodiment, advantageously:

-   -   R⁵ is methyl, ethyl or phenyl, and     -   R⁶ is methyl or i-propyl.

In a third preferred embodiment, R³ and R⁴ are methyls, and R⁷ is a hydrogen atom. In this third embodiment, advantageously:

-   -   R⁵ is methyl or ethyl, and     -   R⁶ is selected from the group consisting of methyl, i-propyl and         1-propen-1-yl.

Particular preferred compounds of formula (I) are those of table hereafter:

R₃ R₄ R₅ R₆ R₇ Olfactive profile Iaa H H Me Me H green, earthy, roasted nuts, coffee Iab H H Me n-C₅H₁₁ H green, fatty Iac H H Me

H green, ripe fruit Iad H H Me Ph H green Iae H H Me Bz H floral (mimosa, carnation), spicy (eugenol), honey Iaf H H Me Et H powerful, spicy (curry, eugenol), hazelnut, fenugrec, coffee beans, celery, tagete, immortelle, fruity (pear, apple, carrot) Iah H H Me Me Me green, minty, fresh Iai H H Me Me n-Bu camphoraceous, pharmaceuticals, caoutchouc Iaj H H Me —(CH₂)₄— peanut, animal, clean Iak H H Me

H green, floral, a bit animalic Ial H H Me —[CH═CH—(CH₂)₃]— herbaceous, earthy, spicy Ibg H H Et i-Pr H herbaceous, camomile Ica H H Ph Me H spicy, exotic fruits Ida H H i-Bu Me H leathery, cresol I′aa H t-Bu Me Me H sulfur, fatty I′bg H t-Bu Et i-Pr H herbaceous, camomile, woody I′ca H t-Bu Ph Me H green, chemicals I″aa Me Me Me Me H aromatic, woody, powerful. I″ac Me Me Me

H herbal, minty, fruity I″bg Me Me Et i-Pr H herbaceous

The compounds of formula (I) as defined above exhibit interesting olfactive properties. Very unexpectedly and surprisingly, they do not show the typical floral, ambery or fruity notes that the skilled person would have expected, but rather green and/or spicy notes.

In another aspect, the invention therefore relates to the use of the compounds of formula (I) as described above as fragrant agents. This invention also relates to a fragrant composition containing at least one compound of formula (I) according to the invention.

This invention includes any fragrant composition comprising, as a fragrant or flavouring agent, at least a compound of formula (I). The compounds of the invention may be used alone or in combination with other perfuming ingredients, solvents, additives or fixatives, commonly used and that the person skilled in the art is able to choose in regard of the desired effect and the nature of the product to perfume.

In a first embodiment, the invention relates to the use of a compound of formula (I) according to the invention or a composition containing at least one of such a compound in the perfumery field for the preparation of perfumed bases and concentrates, fragrances, perfumes and similar products (e.g. topic compositions, cosmetic compositions such as for example face and body creams, cleansers, facial treatments, talc powders, hair oils, shampoos, hair lotions, bath oils and salts, shower and bath gels, soaps, body anti-perspirants and deodorizers, pre-shave, shaving and post-shave creams and lotions, creams, toothpastes, mouth baths, pomades, cleaning products, such as for example softeners, detergents, air deodorizers and household cleaning supplies. Therefore, the invention also relates to a fragrant composition including at least one compound of formula (I).

In a second embodiment, the invention relates to the use of the compounds or composition as described above, as masking agents of odours, and to any pharmaceutical or cosmetic composition containing at least one compound of formula (I) or one or more isomers of a compound of formula (I). Therefore, this invention also relates to any composition comprising at least one compound of formula (I), as herein described, in combination with any suitable excipient, especially pharmaceutical or cosmetic excipient.

In another aspect, the invention also relates to a method of fragrancing a composition by adding an olfactory effective amount of a compound of formula (I) of the invention to said composition. Suitable compositions comprise perfumed bases and concentrates, fragrances, perfumes and similar products; topic compositions; cosmetic compositions such as for example face and body creams, cleansers, facial treatments, talc powders, hair oils, shampoos, hair lotions, bath oils and salts, shower and bath gels, soaps, body anti-perspirants and deodorizers, pre-shave, shaving and post-shave creams and lotions, creams, toothpastes, mouth baths, pomades; cleaning products, such as for example softeners, detergents, air deodorizers and household cleaning supplies.

In yet another aspect, the invention also relates to a method of masking odours comprising adding an olfactory effective amount of at least a compound of formula (I) of the invention to a composition. Suitable compositions comprise particularly pharmaceutical, and cosmetic compositions. Suitable cosmetic composition include face and body creams, cleansers, facial treatments, talc powders, hair oils, shampoos, hair lotions, bath oils and salts, shower and bath gels, soaps, body anti-perspirants and deodorizers, pre-shave, shaving and post-shave creams and lotions, creams, toothpastes, mouth baths, and pomades.

The compounds of the invention may be used in a concentration comprised in a range from 0.001% to 99% in weight, preferably from 0.1% to 50% in weight, more preferably from 0.1% to 30% in weight. It is known by the man skilled in the art that these values depend of the nature of the composition/article to be perfumed, the desired intensity of the perfume, and of the nature of the other ingredients present in said composition or article.

The invention also relates to a process of preparing a compound according formula (I) as defined above, the process comprising the following steps of:

-   -   a) reacting a compound of formula (II) with morpholine so as to         obtain an enamine of formula (III)

-   -   -   wherein R³ and R⁴ are as defined above,

    -   b) acylating the enamine of formula (III) with R⁵—COCl, wherein         R⁵ is as defined above, so as to obtain the corresponding         acylated enamine

-   -   c) hydrolysing the acylated enamine obtained in the previous         step in the presence of an acid, such as for example         hydrochloric acid so as to obtain a diketone of formula (IV)

-   -   d) reducing the diketone (IV) so as to obtain the corresponding         diol (V)

and

-   -   e) reacting the diol (V) with R⁶—CO—R⁷, wherein R⁶ and R⁷ are as         defined above, so as to obtain the compound of formula (I)

Step a) of the process of the invention is carried out in an organic solvent, which may be selected from the group comprising toluene, xylene, trimethylbenzene, cyclohexane, and methylcyclohexane. According to a preferred embodiment, the organic solvent is cyclohexane or toluene.

The reaction of step a) is advantageously carried out at refluxing temperature.

Step b) is carried out in an organic solvent, which may be selected from the group comprising toluene, xylene, trimethylbenzene, cyclohexane and methylcyclohexane, in the presence of an amine, preferably triethylamine. According to a preferred embodiment, the organic solvent is toluene.

Step c) is advantageously carried out in the same solvent as step b). Preferably, the diketone is directly reacted with the acid without previous purification.

The reduction of the diketone to the diol in step d) is carried out according to conventional reduction methods well known to the person skilled in the art, e.g. using NaBH₄, Dibal-H, LiAlH₄ or H₂. Particularly good results were obtained with NaBH₄.

DEFINITIONS

The terms “fragrance” and “fragrant” are used interchangeably whenever a compound or a mixture of compounds is referred to, which is intended to pleasantly stimulate the sense of smell.

The term “olfactory effective amount” means a level or amount of fragrant compound present in a material at which the incorporated compound exhibits a sensory effect.

By the term “masking” is meant reducing or eliminating malodour perception generated by one or more molecules entering in the composition of a product.

The term “isomer” means molecules having the same chemical formula, which means same number and types of atoms, but in which the atoms are arranged differently.

The term “isomer” includes structural isomers, geometric isomers, optical isomers and stereoisomers. It particularly includes the cis/trans isomers, the cis isomers being the ones where the bicyclic junction is cis, i.e. the substituents forming the acetal cycle are on the same side of the cyclohexyl cycle in (I). The trans configuration is the one where the substituents forming the acetal cycle are on two different sides of the cyclohexyl cycle in (I)—the bicyclic junction is trans.

The term “C1-C6 alkyl” or “C1-C6 alkyl group”, means any linear or branched saturated hydrocarbon chain having 1, 2, 3, 4, 5 or 6 carbon atoms, such as for example methyl, ethyl, n-propyl, i-propyl, n-butyl, sec-butyl, iso-butyl, tert-butyl, and n-pentyl.

The term “C2-C6 alkenyl” or “C2-C6 alkenyl group”, means any linear or branched mono or poly unsaturated hydrocarbon chain, having 2, 3, 4, 5 or 6 carbon atoms, such as for example ethenyl, prop-1-enyl, allyl, but-1-enyl, but-2-enyl or pentenyl.

The term “C5-C6 cycloalkyl” or “C5-C6 cycloalkyl group”, means any cyclic saturated hydrocarbon chain having 5 or 6 carbon atoms (namely, a cyclopentyl or cyclohexyl), substituted or not by one or several alkyl and/or alkenyl groups as described above—preferably methyl and ethyl—.

The term “C5-C6 cycloalkenyl” or “C5-C6 cycloalkenyl group”, means any cyclic mono or poly unsaturated hydrocarbon chain having preferably 5, 6 or 7 carbon atoms, such as for example cyclopentenyl, cyclohexenyl and cycloheptenyl, substituted or not by one or several alkyl and/or alkenyl groups as described above—preferably methyl and ethyl—.

The term “aryl” refers to a polyunsaturated, aromatic hydrocarbyl group having a single ring (i.e. phenyl) or multiple aromatic rings fused together (e.g. naphtyl) or linked covalently, typically containing 5 to 12 atoms; preferably 6 to 10, wherein at least one ring is aromatic. A preferred aryl group is phenyl. The term “(CH₂)₀₋₂-aryl” thus includes any aryl group as defined above as well as any —CH₂-aryl group and any —(CH₂)₂-aryl group, wherein the aryl moiety is as defined above. A preferred —CH₂-aryl group is the benzyl group and a preferred —(CH₂)₂-aryl group is —(CH₂)₂-phenyl.

The invention will be better understood with reference to the following examples. These examples are intended to be representative of specific embodiments of the invention, and are not intended as limiting the scope of the invention.

EXAMPLES Example 1 Preparation of 4-cyclohex-1-enyl-morpholine (III)

Cyclohexanone (98.14 g, 1.00 mol) is added dropwise to a 12M solution of morpholine (118.48 g, 1.36 mol) in cyclohexane (120 ml) at 65-70° C. The reaction mixture is then heated under reflux and the completion of the reaction is followed by GC. The formed water is removed using a Dean-Stark apparatus.

After cooling down, the solvent is removed under vacuum and the crude 4-cyclohex-1-enyl-morpholine (orange liquid, quantitative yield) is used directly in the following step.

Example 2 Preparation of 4-(4-tert-butyl-cyclohex-1-enyl)-morpholine (III′)

Compound III′ (white solid) is obtained quantitatively according to Example 1, from 4-tert-butylcyclohexanone (77.12 g, 0.50 mol), morpholine (54.01 g, 0.62 mol) and cyclohexane (60 mL).

Example 3 Preparation of 4-(4,4-dimethyl-cyclohex-1-enyl)-morpholine (III″)

Compound III″ (brown liquid) is obtained quantitatively according to Example 1, from 4,4-dimethylcyclohexanone (350.03 g, 2.76 mol), morpholine (327.01 g, 3.75 mol) and cyclohexane (330 mL).

Example 4 Preparation of 2-acetyl-cyclohexanone (IVa)

To a 0.65 M solution of 4-cyclohex-1-enyl-morpholine (82.64 g, 0.50 mol, 1 eq.), obtained in Example 1, in toluene (770 ml) is added triethylamine (71.33 g, 0.70 mol, 1.41 eq). Acetyl chloride (55.34 g, 0.70 mol, 1.41 eq)) is then added dropwise and the reaction mixture is further stirred at 35° C. for 20 hours and then at room temperature overnight.

After completion of the reaction (followed by GC), a 20% HCl aqueous solution (250 mL) is added and the mixture is stirred under reflux for 1 hour.

After cooling down, the organic phase is washed twice with water, once with saturated aqueous NaHCO₃ solution and with brine. The organic phase is then dried over magnesium sulphate and the solvents are evaporated. The crude oil is then purified by distillation to give compound IVa as a colourless oil (49.95 g, 0.36 mol, 72% yield).

Bp: 48° C./0.6 torr

Example 5 Preparation of 2-propionyl-cyclohexanone (IVb)

Compound IVb is obtained in 49% yield as a colourless oil, according to Example 4, from 4-cyclohex-1-enyl-morpholine (82.64 g, 0.50 mol, obtained in Example 1), triethylamine (71.33 g, 1.41 mol), propionyl chloride (64.76 g, 1.41 mol), toluene (770 mL) and 20% aqueous HCl (250 mL).

Bp: 98° C./5.4 torr

Example 6 Preparation of 2-benzoyl-cyclohexanone (IVc)

Compound IVc is obtained in 50% yield as a yellow powder, according to Example 4, from 4-cyclohex-1-enyl-morpholine (40.96 g, 0.25 mol, obtained in Example 1), triethylamine (35.35 g, 0.35 mol), benzoyl chloride (49.19 g, 0.35 mol), toluene (380 mL) and 20% aqueous HCl (125 mL).

Bp: 110° C./0.3 torr

Example 7 Preparation of 2-(3-methylbutanoyl)cyclohexanone (IVd)

Compound IVd is obtained in 90% yield as a pale yellow liquid, according to Example 4, from 4-cyclohex-1-enyl-morpholine (82.64 g, 0.5 mol, obtained in Example 1), triethylamine (71.34 g, 0.71 mol), isovaleryl chloride (85.01 g, 0.71 mol), toluene (760 mL) and 20% aqueous HCl (166 mL).

Bp: 76° C./0.68 torr

Example 8 Preparation of 2-acetyl-4-tert-butyl-cyclohexanone (IV′a)

Compound IV′a is obtained in 53% yield as a yellow oil, according to Example 4, from morpholino-enamine III′ (36.89 g, 0.17 mol, obtained in Example 2), triethylamine (24.25 g, 0.24 mol), acetyl chloride (18.84 g, 0.24 mol), toluene (260 mL) and 20% aqueous HCl (85 mL).

Bp: 74° C./0.5 torr

Example 9 Preparation of 4-tert-butyl-2-propionyl-eyelohexanone (IV′b)

Compound IV′b is obtained in 58% yield as a yellow oil, according to Example 4, from morpholino-enamine III′ (36.89 g, 0.17 mol, obtained in Example 2), triethylamine (24.25 g, 0.24 mol), propionyl chloride (22.2 g, 0.24 mol), toluene (260 mL) and 20% aqueous HCl (85 mL).

Bp: 98° C./0.7 torr

Example 10 Preparation of 2-benzoyl-4-tert-butyl-cyclohexanone (IV′c)

Compound IV′c is obtained in 35% yield as a yellow powder, according to Example 4, from morpholino-enamine III′ (36.89 g, 0.17 mol, obtained in Example 2), triethylamine (24.25 g, 0.24 mol), benzoyl chloride (33.73 g, 0.24 mol), toluene (260 mL) and 20% aqueous HCl (85 mL).

Bp: 110° C./0.2 torr

Example 11 Preparation of 2-((E)-but-2-enoyl)-4-tert-butyl-cyclohexanone (IV′e)

Compound IV′e is obtained as white crystals, according to Example 4, from morpholino-enamine III′ (55.33 g, 0.25 mol, obtained in Example 2), triethylamine (35.66 g, 0.35 mol), crotonyl chloride (36.85 g, 0.35 mol), toluene (380 mL) and 20% aqueous HCl (125 mL).

Bp: 115° C./0.76 torr

Mp: 73.6° C.

Example 12 Preparation of 2-acetyl-4,4-dimethyl-cyclohexanone (IV″a)

Compound IV″a is obtained in 33% yield as a pale yellow oil, according to Example 4, from morpholino-enamine III″ (266.36 g, 1.36 mol, obtained in Example 3), triethylamine (194.04 g, 1.91 mol), acetyl chloride (149.93 g, 1.91 mol), toluene (2.09 L) and 20% aqueous HCl (685 mL).

Bp: 98° C./6.1 torr

Example 13 Preparation of 4,4-dimethyl-2-propionyl-cyclohexanone (IV″b)

Compound IV″b is obtained in 26% yield as a orange oil, according to Example 4, from morpholino-enamine III″ (131.88 g, 0.67 mol, obtained in Example 3), triethylamine (95.59 g, 0.94 mol), propionyl chloride (86.96 g, 0.94 mol), toluene (1.03 L) and 20% aqueous HCl (340 mL).

Bp: 64° C./1.1 torr

Example 14 Preparation of 2-(1-hydroxy-ethyl)-cyclohexanol (Va)

Diketone IVa (49.95 g, 0.36 mol, 1 eq., obtained in Example 4) is added dropwise to a 10-15° C. molar suspension of NaBH₄ (13.47 g, 0.36 mol, 1 eq.) in EtOH (360 ml). After completion of the reaction (followed by tlc), acetone (65 ml) is added to the reaction mixture. Half of the solvents is then evaporated and the mixture is diluted in water and MTBE. 10% aqueous HCl is added and the aqueous phase is extracted three times with MTBE. The combined organic phases are then washed with saturated aqueous NaHCO₃ and with brine. After drying over magnesium sulphate, the organic phase is filtered and the solvents are evaporated to give crude diol Va as a pale yellow oil in quantitative yield. Compound Va is used in the next step without further purification.

Example 15 Preparation of 2-(1-hydroxy-propyl)-cyclohexanol (Vb)

Compound Vb is obtained in 93% yield as a yellow oil, according to Example 4 from diketone IVb (37.73 g, 0.24 mol, obtained in Example 5), NaBH₄ (9.14 g, 0.24 mol), ethanol (240 mL) and acetone (40 mL).

Example 16 Preparation of 2-(hydroxy-phenyl-methyl)-cyclohexanol (Vc)

Compound Ve is obtained in quantitative yield as a pale yellow oil, according to Example 14, from diketone IVc (25.03 g, 0.12 mol, obtained in Example 6), NaBH₄ (4.67 g, 0.12 mol), ethanol (120 mL) and acetone (20 mL).

Example 17 Preparation of 2-(1-hydroxy-3-methylbutyl)cyclohexanol (Vd)

Compound Vd is obtained in quantitative yield as a colourless oil, according to Example 14, from diketone IVd (46.02 g, 0.25 mol, obtained in Example 7), NaBH₄ (9.45 g, 0.25 mol), ethanol (240 mL) and acetone (45 mL).

Example 18 Preparation of 4-tert-butyl-2-(1-hydroxy-ethyl)-cyclohexanol (V′ a)

Compound V′a is obtained in quantitative yield as a yellow oil, according to Example 14, from diketone IV′a (15.5 g, 0.08 mol, obtained in Example 8), NaBH₄ (3.02 g, 0.08 mol), ethanol (80 mL) and acetone (15 mL).

Example 19 Preparation of 4-tert-butyl-2-(hydroxy-propyl-methyl)-cyclohexanol (V′b)

Compound V′b is obtained in quantitative yield as a yellow oil, according to Example 14, from diketone IV'b (16.7 g, 0.08 mol, obtained in Example 9), NaBH₄ (3.02 g, 0.08 mol), ethanol (80 mL) and acetone (15 mL).

Example 20 Preparation of 4-tert-butyl-2-(hydroxy-phenyl-methyl)-cyclohexanol (V′c)

Compound V′c is obtained in 78% yield as a white powder, according to Example 14, from diketone IV'c (14.56 g, 0.06 mol, obtained in Example 10), NaBH₄ (2.27 g, 0.06 mol), ethanol (60 mL) and acetone (10 mL).

Example 21 Preparation of 2-(1-hydroxy-ethyl)-4,4-dimethyl-cyclohexanol (V″a)

Compound V″a is obtained in quantitative yield as a pale yellow oil, according to Example 14, from diketone IV″a (72.17 g, 0.43 mol, obtained in Example 12), NaBH₄ (16.25 g, 0.43 mol), ethanol (430 mL) and acetone (85 mL).

Example 22 Preparation of 2-(1-hydroxy-propyl)-4,4-dimethyl-cyclohexanol (V″b)

Compound V″b is obtained in quantitative yield as a pale yellow oil, according to Example 14, from diketone IV″b (29.99 g, 0.16 mol, obtained in Example 13), NaBH₄ (6.05 g, 0.16 mol), ethanol (160 mL) and acetone (30 mL).

Example 23 Preparation of 2,4-dimethyl-hexahydro-benzo[1,3]dioxine (Iaa)

Acetaldehyde (28.81 g, 0.40 mol) is added dropwise to a 2.3M solution of diol Va (28.63 g, 0.20 mol, obtained in Example 14) in refluxing cyclohexane (85 ml). The reaction is catalysed with PTSA. The reaction mixture is refluxed for a further 2 hours and the formed water is removed with a Dean-Stark apparatus.

After completion of the reaction (followed by GC), the reaction mixture is cooled down and poured into a half-saturated aqueous NaHCO₃ solution. The aqueous phase is extracted twice with MTBE and the combined organic layers are washed with a saturated aqueous NaHCO₃ solution and with brine and then dried over magnesium sulphate. The solvents are evaporated and the crude product is purified by distillation to give compound Iaa as a colourless oil in 25% yield. It consists in a mixture of 5 isomers with 2 major isomers (83%) as cis and trans isomers in a 70:30 ratio.

Bp: 65° C./6.5 torr

Olfactory profile: Green, earthy, roasted nuts, coffee

Major Cis-Isomers:

¹H-NMR (200 MHz, CDCl₃): δ (ppm) 0.70-1.80 (m, 8H); 1.12 (d, 3H, J=6.5 Hz,); 1.32 (d, 3H, J=5.1 Hz,); 1.88 (m, 1H); 3.76 (m, 2H); 4.72 (q, 1H, J=5.1 Hz).

¹³C-NMR (50 MHz, CDCl₃): δ (ppm) 17.8; 19.4; 20.5; 21.2; 25.2; 31.7; 39.1; 75.3; 75.5; 98.7.

MS [e/m (%)]: 169 (M⁺, 5); 155 (10); 127 (3); 109 (39); 98 (9); 93 (11); 89 (29); 82 (100); 67 (75); 55 (16); 43 (18); 41 (15).

Major Trans-Isomers:

¹H-NMR (200 MHz, CDCl₃, selected data): δ (ppm) 1.17 (d, 3H, J=6.3 Hz); 1.32 (d, 3H, J=5, 1 Hz); 3.21 (dt, 1H, J=4.0 Hz, J=10.2 Hz); 3.38 (dq, 1H, J=6.3 Hz, J=9.5 Hz); 4.78 (q, 1H, J=5.1 Hz).

¹³C-NMR (50 MHz, CDCl₃): δ (ppm) 18.5; 21.2; 24.6; 25.3; 25.8; 31.6; 47.2; 76.9; 80.5; 98.4.

MS [e/m (%)]: 169 (M⁺, 16); 155 (92); 127 (7); 109 (74); 98 (12); 93 (15); 89 (17); 82 (100); 67 (96); 55 (26); 43 (27); 41 (21).

Minor Cis-Isomers:

¹H-NMR (200 MHz, CDCl₃, selected data): δ (ppm) 5.00 (q, 1H, J=5.0 Hz). ¹³C-NMR (50 MHz, CDCl₃, selected data): δ (ppm) 91.4.

MS [e/m (%)]: idem major cis-isomers.

Example 24 Preparation of 4-methyl-2-pentyl-hexahydro-benzo[1,3]dioxine (Iab)

Compound Iab is obtained as a colourless oil in 20% yield, according to Example 23, from diol Va (28.63 g, 0.2 mol, obtained in Example 14), hexanal (24.03 g, 0.24 mol) and cyclohexane (85 ml). It consists in a mixture of 3 isomers with 2 major isomers (98%) in a 50:50 ratio.

Bp: 80° C./0.6 torr

Olfactory profile: green, fatty

1^(st) Isomers:

¹H-NMR (200 MHz, CDCl₃): δ (ppm) 0.87 (t, 3H, J=6.6 Hz); 1.05-1.20 (m, 3H); 1.06-1.81 (m, 16H); 1.91 (m, 1H); 3.75 (m, 2H); 4.56 (t, 1H, J=4.8 Hz).

¹³C-NMR (50 MHz, CDCl₃): δ (ppm) 14.1; 17.8; 19.4; 20.5; 22.6; 23.6; 25.2; 31.7; 31.8; 35.1; 39.3; 75.2; 75.5; 101.9.

MS [e/m (%)]; 225 (M⁺, 8); 155 (64); 145 (8); 127 (4); 109 (100); 83 (20); 82 (59); 67 (46); 55 (20); 43 (13); 41 (15).

2^(nd) Isomers:

¹H-NMR (200 MHz, CDCl₃, selected data): δ (ppm) 3.20 (dt, 1H, J=4.0 Hz, J=10.3 Hz); 3.37 (dq, 1H, J=6.2 Hz, J=9.5 Hz); 4.60 (t, 1H, J=5.2 Hz).

¹³C-NMR (50 MHz, CDCl₃): δ (ppm) 14.0; 18.6; 22.5; 24.0; 24.6; 25.4; 25.9; 31.7; 31.8; 35.1; 39.3; 77.0; 80.6; 101.8.

MS [e/m (%)]: 225 (M⁺, 13); 155 (100); 145 (3); 127 (5); 109 (64); 83 (15); 82 (36); 67 (35); 55 (18); 43 (11); 41 (13).

Example 25 Preparation of 4-methyl-2-propenyl-hexahydro-benzo[1,3]dioxine (Iac)

Compound Iac is obtained as a colourless oil in 20% yield, according to Example 23, from diol Va (25.96 g, 0.18 mol, obtained in Example 14), crotonaldehyde (15.14 g, 0.21 mol) and cyclohexane (75 ml). It consists in a mixture of 5 isomers with 2 major isomers (85%) as cis and trans isomers in a 62:38 ratio.

Bp: 62° C./0.6 torr

Olfactory profile: green, ripe fruit

Major Cis-Isomers:

¹H-NMR (200 MHz, CDCl₃): δ (ppm) 0.75-1.85 (m, 8H); 1.16 (d, 3H, J=6.5 Hz); 1.73 (d, 3H, J=6.4 Hz); 1.95 (m, 1H); 3.85 (m, 2H); 4.98 (d, 1H, J=6.0 Hz); 5.61 (m, 1H); 5.90 (dq, 1H, J=0.5 Hz, J=6.4 Hz).

¹³C-NMR (50 MHz, CDCl₃): δ (ppm) 17.4; 17.5; 19.0; 20.1; 24.8; 31.4; 38.9; 75.1; 75.3; 101.0; 128.4; 130.5.

MS [e/m (%)]; 195 (M⁺, 6); 181 (10); 155 (1); 127 (3); 109 (68); 82 (14); 71 (100); 69 (18); 67 (44); 55 (17); 41 (19).

Major Trans-Isomers:

¹H-NMR (200 MHz, CDCl₃, selected data): δ (ppm) 1.22 (d, 3H, J=6.2 Hz,); 1.74 (d, 3H, J=6.5 Hz); 3.29 (m, 1H); 3.48 (dq, 1H, J=6.2 Hz, J=9.5 Hz); 5.06 (d, 1H, J=5.7 Hz); 5.97 (dq, 1H, J=0.5 Hz, J=6.5 Hz).

¹³C-NMR (50 MHz, CDCl₃): δ (ppm) 17.3; 18.3; 24.3; 25.0; 25.6; 31.3; 47.0; 80.2; 80.3; 101.4; 128.1; 130.4.

MS [e/m (%)]: 195 (M⁺, 13); 181 (59); 155 (4); 127 (2); 109 (50); 82 (18); 71 (100); 69 (25); 67 (48); 55 (25); 41 (23).

Example 26 Preparation of 4-methyl-2-phenyl-hexahydro-benzo[1,3]dioxine (Iad)

Compound lad is obtained as a pale yellow oil in 44% yield, according to Example 23, from diol Va (14.98 g, 0.1 mol, obtained in 14), benzaldehyde (21.22 g, 0.2 mol) and cyclohexane (50 ml). It consists in a mixture of 5 isomers with 2 major isomers (84%) as cis/trans isomers in a 60:40 ratio.

Bp: 102° C./0.5 torr

Olfactory profile: green

Major Cis-Isomers:

¹H-NMR (200 MHz, CDCl₃): δ (ppm) 0.82-1.43 (m, 2H); 1.23 (d, 3H, J=6.5 Hz); 1.44-1.95 (m, 6H); 2.03 (m, 1H); 4.02 (m, 2H); 5.57 (s, 1H); 7.37 (m, 3H); 7.55 (m, 2H).

¹³C-NMR (50 MHz, CDCl₃): δ (ppm) 17.9; 20.5; 24.6; 25.2; 31.7; 39.2; 75.9; 76.2; 101.7; 126.4; 128.2; 128.7; 139.2.

MS [e/m (%)]: 231 (M⁺, 80); 155 (2); 109 (43); 107 (100); 105 (36); 81 (20); 79 (23); 77 (23); 67 (32); 51 (5); 39 (6).

Major Trans-Isomers:

¹H-NMR (200 MHz, CDCl₃, selected data): δ (ppm) 1.30 (d, 3H, J=6.2 Hz); 3.48 (m, 1H); 3.65 (dq, 1H, J=6.2 Hz, J=9.5 Hz); 5.65 (s, 1H).

¹³C-NMR (50 MHz, CDCl₃): δ (ppm) 18.6; 19.5; 25.4; 25.9; 31.7; 47.4; 77.6; 81.1; 101.0; 126.2; 128.2; 128.6; 138.8.

MS [e/m (%)]: 231 (M⁺, 100); 155 (8); 109 (21); 107 (75); 105 (44); 81 (14); 79 (21); 77 (21); 67 (36); 51 (5); 39 (6).

Minor Isomers:

¹H-NMR (200 MHz, CDCl₃, selected data): δ (ppm) 5.89 (s, 1H).

¹³C-NMR (50 MHz, CDCl₃, selected data): δ (ppm) 32.1.

¹H-NMR (200 MHz, CDCl₃, selected data): δ (ppm) 5.84 (s, 1H).

¹³C-NMR (50 MHz, CDCl₃, selected data): δ (ppm) 31.7.

¹H-NMR (200 MHz, CDCl₃, selected data): δ (ppm) 5.94 (s, 1H).

¹³C-NMR (50 MHz, CDCl₃, selected data): δ (ppm) 31.4.

Example 27 Preparation of 2-benzyl-4-methyl-hexahydro-benzo[1,3]dioxine (Iae)

Compound Iae is obtained as colourless oil in 30% yield, according to Example 23, from diol Va (25.96 g, 0.18 mol, obtained in Example 14), phenylacetaldehyde (25.23 g, 0.21 mol) and cyclohexane (75 ml). It consists in a mixture of 4 isomers with 2 major isomers (93%) as cis/trans isomers in a 75:25 ratio.

Bp: 90° C./0.2 torr

Olfactory profile: Floral (mimosa, carnation), spicy (eugenol), honey.

Major Cis-Isomers:

¹H-NMR (200 MHz, CDCl₃): δ (ppm) 1.10 (d, 3H, J=6.6 Hz); 1.20-1.83 (m, 8H); 1.88 (m, 1H); 2.91 (d, 2H, J=5.0 Hz); 3.69 (m, 2H); 4.70 (t, 1H, J=5.0 Hz); 7.23 (m, 5H).

¹³C-NMR (50 MHz, CDCl₃): δ (ppm) 17.8; 19.4; 20.5; 25.2; 31.7; 39.2; 41.7; 75.3; 75.5; 101.9; 126.1; 127.9; 129.9; 137.2.

MS [e/m (%)]: 245 (M⁺, 1); 155 (52); 121 (3); 109 (100); 91 (31); 67 (25); 55 (8); 43 (5); 41 (8).

Major Trans-Isomers:

¹H-NMR (200 MHz, CDCl₃, selected data): δ (ppm) 1.16 (d, 3H, J=6.3 Hz); 2.91 (d, 2H, J=5.0 Hz); 3.16 (dt, 1H, J=4.0 Hz, J=10.3 Hz); 3.34 (dq, 1H, J=6.3 Hz, J=9.5 Hz); 4.74 (t, 1H, J=5.0 Hz).

¹³C-NMR (50 MHz, CDCl₃): δ (ppm) 18.6; 24.5; 25.4; 25.9; 31.6; 41.8; 47.6; 77.1; 80.6; 102.0; 126.2; 128.0; 129.7; 137.1.

MS [e/m (%)]: 245 (M⁺, 4); 155 (83); 121 (2); 109 (100); 91 (33); 67 (28); 55 (12); 43 (9); 41 (11).

Example 28 Preparation of 2-ethyl-4-methylhexahydro-4H-benzo[d][1,3]dioxine (Iaf)

Compound Iaf is obtained as colourless oil in 60% yield, according to Example 23, from diol Va (25.96 g, 0.18 mol, obtained in Example 14), propionaldehyde (51 g, 0.88 mol) and cyclohexane (450 ml). It consists principally in a mixture of 5 isomers with 3 major isomers (78%) in a 47:31:22 ratio.

Bp: 80-83° C./5.7 torr

Olfactory profile: powerful, spicy (curry, eugenol), hazelnut, fenugrec, coffee beans, celery, tagete, immortelle, fruity (pear, apple, carrot).

1^(st) Major Cis-Isomers:

¹H-NMR (200 MHz, CDCl₃): δ (ppm) 0.70-1.05 (m, 1H); 0.92 (t, J=7.5 Hz, 3H); 1.05-1.53 (m, 5H); 1.17 (d, J=6.2 Hz, 3H); 1.53-1.73 (m, 3H); 1.73-2.05 (m, 2H); 3.19 (dt, J=10.1, 4.00 Hz, 1H); 3.38 (tt, J=9.5, 5.3 Hz, 1H); 4.54 (t, J=5.2 Hz, 1H).

¹³C-NMR (50 MHz, CDCl₃): δ (ppm) 8.62; 18.56; 24.59; 25.38; 25.88; 28.13; 31.66; 47.54; 76.94; 80.49; 102.70.

MS [e/m (%)]: 184 (M⁺, 1); 183 (10); 155 (63); 109 (82); 93 (11); 83 (14); 82 (79); 81 (17); 79 (13); 67 (100); 59 (19); 57 (27); 55 (37); 54 (21); 53 (13); 43 (21); 41 (34); 39 (18).

2^(nd) Major Trans-Isomers:

¹H-NMR (200 MHz, CDCl₃, selected data): δ (ppm) 0.93 (t, J=7.61 Hz, 3H); 1.12 (d, J=6.54 Hz, 3H); 3.67-3.85 (m, 2H); 4.51 (t, J=4.65 Hz, 1H).

¹³C-NMR (50 MHz, CDCl₃): δ (ppm) 8.19; 17.8; 19.39; 20.53; 26.63; 28.06; 31.76; 39.32; 75.17; 75.41; 102.50.

MS [e/m (%)]: 184 (M⁺, <1); 183 (4); 155 (29); 109 (80); 103 (14); 93 (11); 83 (14); 82 (100); 81 (14); 79 (13); 67 (100); 59 (17); 57 (20); 55 (29); 54 (20); 43 (19); 41 (30); 39 (15).

3^(rd) Major Trans-Isomers:

¹H-NMR (200 MHz, CDCl₃, selected data): δ (ppm) 0.90 (t, J=7.64 Hz, 3H); 1.23 (d, J=6.96 Hz, 3H); 3.45-3.57 (m, 1H); 4.0-4.15 (m, 1H); 4.78 (t, J=5.01 Hz, 1H).

¹³C-NMR (50 MHz, CDCl₃): δ (ppm) 8.45; 13.08; 25.23; 25.67; 28.23, 32.14; 43.89; 71.67; 74.18, 95.27.

MS [e/m (%)]: 184 (M⁺, 1); 183 (9); 155 (66); 127 (10); 109 (100); 93 (13); 83 (12); 82 (40); 81 (15); 79 (11); 67 (90); 59 (15); 57 (33); 55 (37); 54 (17); 53 (12); 43 (19); 41 (32); 39 (17).

1^(st) Minor Isomers:

¹H-NMR (200 MHz, CDCl₃, selected data): δ (ppm) 1.32 (d, J=7.0 Hz, 3H).

¹³C-NMR (50 MHz, CDCl₃, selected data): δ (ppm) 7.99; 16.18; 20.32; 24.59; 25.62; 28.23; 31.58; 38.94; 69.14; 73.86; 95.07.

MS [e/m (%)]: 184 (M⁺, <1); 183 (4); 155 (40); 109 (100); 93 (11); 83 (10); 82 (30); 81 (11); 79 (9); 67 (70); 59 (10); 57 (19); 55 (26); 54 (11); 43 (14); 41 (23); 39 (11).

2^(nd) Minor Isomers:

¹³C-NMR (50 MHz, CDCl₃, selected data): δ (ppm) 44.2; 74.9; 79.6; 97.6.

MS [e/m (%)]: 184 (M⁺, <1); 183 (2); 155 (40); 109 (100); 93 (5); 83 (10); 82 (38); 81 (12); 79 (10); 67 (73); 59 (17); 57 (21); 55 (29); 54 (15); 43 (16); 41 (26); 39 (13).

Example 29 Preparation of 2,2,4-trimethylhexahydro-4H-benzo[d][1,3]dioxine (Iah)

Compound Iah is obtained as colourless oil in 14% yield, according to Example 23, from diol Va (40.57 g, 0.28 mol, obtained in Example 14), acetone (32.52 g, 0.56 mol) and cyclohexane (110 ml). It consists in a mixture of 4 isomers with 2 major isomers (96%) as cis/trans enantiomers in a 53:47 ratio.

Bp: 44° C./0.6 torr

Olfactory profile: green, minty, fresh.

Major Cis-Isomers:

¹H-NMR (200 MHz, CDCl₃): δ (ppm) 0.70-1.30 (m, 4H), 1.06 (d, J=6.46 Hz, 3H), 1.30-1.65 (m, 21-1), 1.40 (s, 3H), 1.41 (s, 3H), 3.45 (dt, J=9.8 Hz, J=3.6 Hz, 1H), 1.65-1.90 (m, 3H), 3.63 (qd, J=9.64 Hz, J=6.09 Hz, 1H).

¹³C-NMR (50 MHz, CDCl₃): δ (ppm) 18.14, 19.63, 20.18, 25.14, 25.44, 30.06, 31.75, 39.33, 37.97, 68.17, 98.31.

MS [e/m (%)]: 184 (M⁺, <1); 169 (54); 127 (11); 109 (100); 93 (6); 82 (18); 81 (11); 67 (68); 59 (77); 55 (23); 54 (11); 43 (62); 41 (25); 39 (14).

Major Trans-Isomers:

¹H-NMR (200 MHz, CDCl₃, selected data): δ (ppm) 1.11 (d, J=6.09 Hz, 3H), 1.38 (s, 311), 1.45 (s, 3H), 3.90-4.09 (m, 2H).

¹³C-NMR (50 MHz, CDCl₃): δ (ppm) 18.41, 19.02, 19.95, 24.64, 25.80, 30.29, 32.12, 47.76, 69.85, 73.14, 98.29.

MS [e/m (%)]: 184 (M⁺, <1); 169 (100); 127 (19); 109 (94); 93 (10); 82 (26); 81 (15); 67 (83); 59 (95); 55 (35); 54 (15); 43 (89); 41 (34); 39 (21).

Example 30 Preparation of 2-butyl-2,4-dimethylhexahydro-4H-benzo[d][1,3]dioxine (Iai)

Compound Iai is obtained as colourless oil in 10% yield, according to Example 23, from diol Va (40.57 g, 0.28 mol, obtained in Example 14), 2-hexanone (33.65 g, 0.34 mol) and cyclohexane (110 ml). It consists in a mixture of 2 isomers (94%) as cis and trans enantiomers in a 56:44 ratio.

Bp: 60° C./0.47 torr

Olfactory profile: Camphoraceous, pharmaceuticals, caoutchouc.

Major Cis-Isomers:

¹H-NMR (200 MHz, CDCl₃): δ (ppm) 0.80-0.95 (m, 3H); 1.02-1.20 (m, 5H); 1.20-1.50 (m, 10H); 1.50-1.87 (m, 6H); 3.92-4.13 (m, 2H).

¹³C-NMR (50 MHz, CDCl₃, selected data): δ (ppm) 39.07 & 39.38; 67.45 & 67.63; 67.71 & 67.93; 99.35 & 99.41.

MS [e/m (%)]: 226 (M⁺, <1); 211 (29); 169 (29); 127 (7); 109 (100); 101 (30); 85 (17); 67 (42); 57 (13); 55 (20); 43 (44); 41 (18).

Major Trans-Isomers:

¹H-NMR (200 MHz, CDCl₃, selected data): δ (ppm) 3.32-3.52 (m, 1H); 3.61 (ddd, J=10.2 Hz, J=6.1 Hz, J=4.0 Hz, 1H).

¹³C-NMR (50 MHz, CDCl₃, selected data): δ (ppm) 47.47 & 47.96; 69.34 & 69.58; 72.61 & 72.86; 100.19 & 100.26.

MS [e/m (%)]: 226 (M⁺, <1); 211 (92); 169 (88); 127 (15); 109 (100); 101 (53); 85 (44); 81 (14); 67 (61); 57 (26); 55 (40); 43 (86); 41 (34).

Example 31 Preparation of 4-methylhexahydro-4H-spiro[benzo[d][1,3]dioxine-2,1′-cyclopentane] (Iaj)

Compound Iaj is obtained as colourless oil in 16% yield, according to Example 23, from diol Va (40.57 g, 0.28 mol, obtained in Example 14), cyclopentanone (28.26 g, 0.34 mol) and cyclohexane (110 ml). It consists in a mixture of 2 isomers (97%) as cis/trans enantiomers in a 57:43 ratio.

Bp: 64-68° C./0.57 torr

Olfactory profile: Peanut, animal, clean.

Major Cis-Isomers:

¹H-NMR (200 MHz, CDCl₃): δ (ppm) 1.06 (d, J=6.6 Hz); 1.05-1.5 (m, 4H); 1.50-2.0 (m, 9H); 3.83-3.97 (m, 2H).

¹³C-NMR (50 MHz, CDCl₃): δ (ppm) 18.12; 20.31; 22.61; 24.61; 24.64; 25.15; 31.49; 31.81; 39.40; 40.46; 69.49; 69.75; 110.36.

MS [e/m (%)]; 210 (M⁺, 9); 181 (48); 109 (100); 85 (32); 81 (11); 67 (61); 56 (17); 55 (63); 43 (13); 41 (25); 39 (11).

Major Trans-Isomers:

¹H-NMR (200 MHz, CDCl₃, selected data): δ (ppm) 0.70-0.95 (m, 1H); 1.12 (d, J=6.0 Hz, 3H); 3.34 (dt, J=10.2 Hz, J=3.8 Hz, 1H); 3.52 (qd, J=9.8 Hz, J=6.1 Hz, 1H).

¹³C-NMR (50 MHz, CDCl₃): δ (ppm) 18.53; 18.91; 22.53; 24.48; 25.40; 25.86; 31.65; 32.0; 40.55; 47.75; 71.41; 74.80; 110.25.

MS [e/m (%)]: 210 (M⁺, 8); 182 (16); 181 (100); 109 (67); 85 (32); 81 (10); 67 (52); 56 (21); 55 (77); 43 (13); 41 (27); 39 (12).

Example 32 Preparation of 2-(2,4-dimethylcyclohex-3-enyl)-4-methylhexahydro-4H-benzo [d][1,3]dioxine (Iak)

Compound Iak is obtained as colourless oil in 28% yield, according to Example 23, from diol Va (40 g, 0.278 mol, obtained in Example 14), 2,4-dimethylcyclohex-3-enecarbaldehyde (Triplal™, 46 g, 0.333 mol) and cyclohexane (140 ml). It consists in a mixture of isomers, with 4 main isomers (85%) in a 42:31:16:11 ratio (cis/trans ratio: 58:42).

Bp: 105° C./0.4 torr

Olfactory profile: floral, green, a bit animalic.

Major Cis-Isomers:

¹H-NMR (200 MHz, CDCl₃): δ (ppm) 0.86 (d, J=6.8 Hz); 1.05-1.55 (m, 13H); 1.55-2.0 (m, 7H); 1.63 (s, 3H); 2.0-2.3 (m, 1H); 3.65-3.85 (m, 2H); 4.32-4.45 (m, 1H); 5.15 (br s, 1H).

¹³C-NMR (50 MHz, CDCl₃, selected data): δ (ppm) 101.80 & 101.84; 127.56; 132.65.

MS [e/m (%)]: 264 (M⁺, 5); 249 (7); 155 (11); 138 (25); 137 (21); 127 (24); 123 (28); 120 (42); 110 (14); 109 (100); 107 (32); 95 (14); 93 (13); 91 (12); 81 (17); 79 (15); 67 (52); 55 (20); 41 (17).

Major Trans-Isomers:

¹H-NMR (200 MHz, CDCl₃, selected data): δ (ppm) 1.0 (d, J=7.0 Hz, 3H); 2.32-2.48 (m, 1H); 3.10-3.30 (m, 1H); 3.30-3.45 (m, 1H); 4.60-4.70 (m, 1H); 5.33 (br s, 1H).

¹³C-NMR (50 MHz, CDCl₃, selected data): δ (ppm) 103.63 & 103.55; 127.52; 132.95.

MS [e/m (%)]: 264 (M⁺, 7); 249 (11); 155 (30); 138 (18); 137 (22); 127 (19); 123 (22); 120 (32); 110 (13); 109 (100); 107 (31); 95 (13); 93 (13); 91 (12); 81 (16); 79 (13); 67 (46); 55 (23); 41 (19).

Minor Cis-Isomers:

¹H-NMR (200 MHz, CDCl₃, selected data): δ (ppm) 3.65-3.85 (m, 2H); 4.60-4.70 (m, 1H); 5.33 (br s, 1H).

¹³C-NMR (50 MHz, CDCl₃, selected data): δ (ppm) 102.02 & 102.12; 127.16; 133.05.

MS [e/m (%)]: 264 (M⁺, 11); 249 (21); 155 (15); 138 (20); 127 (15); 123 (10); 120 (15); 110 (10); 109 (100); 107 (18); 95 (13); 81 (15); 79 (12); 67 (44); 55 (16); 41 (13).

Minor Trans-Isomers:

¹H-NMR (200 MHz, CDCl₃, selected data): δ (ppm) 3.95-4.15 (m, 2H); 4.85-4.97 (m, 1H); 5.15 (br s, 1H).

¹³C-NMR (50 MHz, CDCl₃, selected data): δ (ppm) 103.38; 127.35.

MS [e/m (%)]: 264 (M⁺, 15); 249 (41); 181 (11); 155 (50); 127 (16); 123 (12); 120 (14); 110 (10); 109 (100); 107 (16); 95 (12); 93 (10); 81 (16); 79 (12); 67 (43); 55 (19); 41 (16).

Example 33 Preparation of 4-methyl-4-a,5,6,7,8,8a-hexahydro-4H-spiro[benzo[d][1,3]dioxine-2,1′-cyclohex[2]ene] (Ial)

Compound Ial is obtained as colourless oil, according to Example 23, from diol Va (40 g, 0.278 mol, obtained in Example 14) and cyclohexenone. It consists in a mixture of isomers in a 25:31:20:24 ratio.

1^(st) Isomers:

MS [e/m (%)]: 222 (M⁺, 15); 168 (97); 109 (100); 97 (12); 81 (13); 79 (16); 77 (12); 68 (22); 67 (55); 55 (24); 54 (24); 43 (10); 41 (26); 39 (19).

2^(nd) Isomers:

MS [e/m (%)]: 222 (M⁺, 44); 168 (12); 109 (100); 97 (14); 96 (47); 81 (28); 79 (18); 68 (18); 67 (59); 55 (15); 54 (22); 53 (11); 43 (13); 41 (25); 39 (17).

3^(rd) Isomers

MS [e/m (%)]: 222 (M⁺, 14); 168 (100); 109 (29); 97 (11); 81 (13); 79 (10); 68 (10); 67 (31); 55 (11); 54 (14).

4^(th) Isomers:

MS [e/m (%)]; 222 (M⁺, 100); 207 (13); 168 (53); 114 (14); 109 (70); 97 (16); 96 (81); 95 (14); 81 (57); 79 (24); 77 (12); 68 (18); 67 (64); 55 (37); 54 (27); 53 (18); 43 (18); 41 (39); 39 (23).

Example 34 Preparation of 4-ethyl-2-isopropyl-hexahydro-benzo[1,3]dioxine (Ibg)

Compound Ibg is obtained as colourless oil in 65% yield, according to Example 23, from diol Vb (35.65 g, 0.23 mol, obtained in Example 15), isobutyraldehyde (32.45 g, 0.45 mol) and cyclohexane (100 mL). It consists in a mixture of 6 isomers with 3 major isomers (85%) in a 63:20:17 ratio. The major enantiomers have the cis configuration.

Bp: 98° C./6.8 torr

Olfactory profile: herbaceous, camomile

1^(st) Major Isomers (Cis-Isomers):

¹H-NMR (200 MHz, CDCl₃): δ (ppm) 0.85-1.00 (m, 3H); 0.94 (d, 3H, J=6.8 Hz); 0.95 (d, 3H, J=6.8 Hz); 1.01-1.82 (m, 10H); 1.83-1.75 (m, 2H); 3.41 (ddd, 1H, J=2.0 Hz, J=6.9 Hz, J=8.0 Hz); 3.72 (m, 1H); 4.30 (d, 1H, J=4.4 Hz).

¹³C-NMR (50 MHz, CDCl₃): δ (ppm) 9.8; 16.7; 17.1; 19.6; 20.3; 24.7; 25.4; 31.9; 32.8; 37.9; 75.0; 81.2; 105.0.

MS [e/m (%)]: 211 (M⁺, 6); 169 (51); 141 (3); 131 (18); 111 (5); 123 (100); 93 (11); 82 (77); 81 (59); 73 (28); 67 (64); 55 (21); 41 (24).

2^(nd) Major Isomers:

¹³C-NMR (50 MHz, CDCl₃, selected data): δ (ppm) 9.4; 25.4; 31.8; 32.8; 45.4; 80.5; 81.7; 105.5.

MS [e/m (%)]: idem 1^(st) major isomer.

3^(rd) Major Isomers:

¹H-NMR (200 MHz, CDCl₃, selected data): δ (ppm) 0.85-1.00 (m, 3H); 0.90 (d, 3H, J=6.8 Hz); 0.91 (d, 3H, J=6.8 Hz); 1.01-1.82 (m, 10H); 1.83-1.98 (m, 2H); 3.42 (m, 1H); 3.70 (ddd, 1H, J=3.9 Hz, J=5.5 Hz, J=11.9 Hz); 4.38 (d, 1H, J=5.6 Hz).

¹³C-NMR (50 MHz, CDCl₃): δ (ppm) 9.9; 16.9; 17.5; 18.5; 24.5; 25.7; 26.4; 32.2; 32.7; 43.9; 74.8; 76.4; 97.9.

MS [e/m (%)]: 211 (M⁺, 6); 169 (75); 141 (5); 123 (100); 111 (38); 93 (21); 82 (17); 81 (66); 73 (11); 67 (46); 55 (22); 41 (20).

1^(st) Minor Isomers

¹³C-NMR (50 MHz, CDCl₃, selected data): δ (ppm) 44.2; 74.9; 79.6; 97.6.

MS [e/m (%)]: idem 3^(rd) major isomer.

Example 35 Preparation of 2-methyl-4-phenyl-hexahydro-benzo[1,3]dioxine (Ica)

Compound Ica is obtained as white crystals in 25% yield, according to Example 23, from diol Vc (24.75 g, 0.12 mol, obtained in Example 16), acetaldehyde (17.29 g, 0.24 mol) and cyclohexane (50 mL). It consists in a mixture of 3 isomers with 1 major enantiomers (84%), as cis-isomers.

Bp: 88° C./0.3 torr

Mp: 57.4° C.

Olfactory profile: Spicy, exotic fruits

Major Cis-Isomers:

¹H-NMR (200 MHz, CDCl₃): δ (ppm) 0.85-1.20 (m, 2H); 1.21-1.51 (m, 2H); 1.47 (d, 3H, J=5.1 Hz); 1.52-1.72 (m, 4H); 1.98 (m, 1H); 4.02 (m, 1H); 4.80 (m, 1H); 4.94 (q, 1H, J=5.1 Hz); 7.29 (m, 5H).

¹³C-NMR (50 MHz, CDCl₃): δ (ppm) 20.1; 20.6; 21.3; 25.4; 31.9; 40.4; 75.4; 81.2; 99.3; 125.5; 126.9; 128.1; 140.4.

MS [e/m (%)]: 189 (1); 188 (1); 171 (1); 151 (15); 129 (4); 117 (6); 107 (100); 91 (16); 82 (41); 67 (52); 54 (16); 41 (8); 39 (6).

1^(st) Minor Isomers:

¹H-NMR (200 MHz, CDCl₃, selected data): δ (ppm) 1.36 (d, 3H, J=5.0 Hz); 3.90 (m, 1H).

¹³C-NMR (50 MHz, CDCl₃, selected data): δ (ppm) 31.7; 47.0; 81.1; 84.3; 93.2; 127.3; 128.3.

2^(nd) Minor Isomers:

¹H-NMR (200 MHz, CDCl₃, selected data): δ (ppm) 1.42 (d, 3H, J=5.1 Hz); 3.42 (dt, 1H, J=4.1 Hz, J=10.5 Hz); 4.23 (d, 1H, J=9.8 Hz); 4.97 (q, 1H, J=5.1 Hz).

Example 36 Preparation of 4-isobutyl-2-methylhexahydro-4H-benzo[d][1,3]dioxine (Ida)

Compound Ida is obtained as a colourless oil in 50% yield, according to Example 23, from diol Vd (24 g, 0.13 mol, obtained in Example 17), acetaldehyde (11.3 g, 0.26 mol) and cyclohexane (100 mL). It consists in a mixture of 6 isomers with 2 major isomers (75%) as cis/trans enantiomers in a 60:40 ratio.

Bp: 60° C./0.5 torr

Olfactory profile: Leathery, cresol.

Major Cis-Isomers:

¹H-NMR (200 MHz, CDCl₃): δ (ppm) 0.88 (d, J=6.6 Hz, 3H); 0.89 (d, J=6.6 Hz, 3H); 1.05-1.37 (m, 4H); 1.33 (d, J=5.1 Hz, 3H); 1.37-1.55 (m, 3H); 1.55-1.80 (m, 3H); 1.80-2.20 (m, 2H); 3.58-3.71 (m, 1H); 3.74-3.80 (m, 1H); 4.72 (q, J=5.09 Hz, 1H).

¹³C-NMR (50 MHz, CDCl₃): δ (ppm) 19.84; 20.56; 21.21; 22.63; 22.94; 24.0; 25.33; 31.81; 38.16; 40.74; 75.43; 77.94; 98.89.

MS [e/m (%)]: 212 (M⁺, <0); 211 (2); 197 (1); 151 (3); 150 (3); 131 (14); 111 (4); 95 (13); 87 (16); (100); 69 (17); 67 (52); 55 (16); 43 (21); 41 (24).

Major Trans-Isomers:

¹H-NMR (200 MHz, CDCl₃, selected data): δ (ppm) 3.15-3.36 (m, 1H); 3.58-3.71 (m, 1H); 4.95 (m, 1H).

¹³C-NMR (50 MHz, CDCl₃, selected data): δ (ppm) 25.72 & 25.79; 32.34 & 34.55; 43.67 & 45.93; 73.48 & 74.71; 78.85 & 80.69; 91.19 & 91.73.

MS [e/m (%)]: 212 (M⁺, <0); 211 (4); 197 (13); 155 (29); 151 (8); 131 (17); 111 (65); 95 (39); 93 (33); 87 (33); 83 (27); 82 (100); 81 (29); 79 (19); 69 (40); 67 (81); 57 (15); 55 (37); 54 (21); 45 (20); 43 (45); 41 (51); 39 (17).

1^(st) Minor Isomers:

¹H-NMR (200 MHz, CDCl₃, selected data): δ (ppm) 3.42-3.60 (m, 1H); 3.96-4.05 (m, 1H); 4.76 (q, J=10.2 Hz, 1H)

¹³C-NMR (50 MHz, CDCl₃, selected data): δ (ppm) 25.38; 31.61; 38.07; 98.56.

MS [e/m (%)]: 212 (M⁺, <0); 211 (3); 197 (27); 155 (26); 151 (10); 131 (7); 111 (100); 95 (53); 93 (45); 83 (18); 82 (61); 81 (31); 79 (17); 69 (40); 67 (72); 55 (36); 54 (18); 45 (15); 43 (40); 41 (46); 39 (15).

2^(nd) Minor Isomers:

¹H-NMR (200 MHz, CDCl₃, selected data): δ (ppm) 5.07 (q, J=9.8 Hz, 1H).

MS [e/m (%)]: 212 (M⁺, <0); 211 (2); 197 (19); 151 (9); 150 (6); 131 (9); 111 (13); 95 (33); 87 (18); 83 (19); 82 (100); 81 (27); 79 (15); 69 (41); 67 (71); 57 (13); 55 (29); 54 (18); 45 (14); 43 (30); 41 (37); 39 (11).

Example 37 Preparation of 6-tert-butyl-2,4-dimethyl-hexahydro-benzo[1,3]dioxine (I′aa)

Compound I′aa is obtained as a yellow oil in 26% yield, according to Example 23, from diol V′a (48.74 g, 0.24 mol, obtained in Example 18), acetaldehyde (35.23 g, 0.49 mol) and cyclohexane (100 mL). It consists in a mixture of 6 isomers with 3 major isomers (65%) in a 42:29:29 ratio.

Bp: 58° C./0.3 torr

Olfactory profile: Sulfur, fatty.

1^(st) Major Isomers (Cis-Isomers):

¹H-NMR (200 MHz, CDCl₃): δ (ppm) 0.86 (s, 9H); 0.90-1.92 (m, 7H); 1.16 (d, 3H, J=6.6 Hz); 1.33 (d, 3H, J=5.1 Hz); 1.99 (m, 1H); 3.73 (m, 1H); 3.83 (m, 1H); 4.74 (q, 1H, J=5.1 Hz).

¹³C-NMR (50 MHz, CDCl₃): δ (ppm) 17.9; 21.2; 21.5; 25.6; 27.6; 32.6; 36.0; 39.8; 47.1; 74.9; 75.5; 98.7.

MS [e/m (%)]: 225, (M⁺, 10); 211 (40); 165 (21); 149 (8); 138 (66); 125 (5); 109 (61); 108 (14); 95 (37); 83 (25); 82 (35); 81 (32); 80 (47); 79 (23); 67 (25); 57 (100); 55 (25); 43 (26); 41 (28).

2^(nd) Major Isomers:

¹H-NMR (200 MHz, CDCl₃, selected data): δ (ppm) 0.85 (s, 9H); 4.68 (q, 1H, J=5.1 Hz).

¹³C-NMR (50 MHz, CDCl₃, selected data): δ (ppm) 20.2; 29.4; 36.0.

MS [e/m (%)]: 225 (M⁺, 2); 211 (2); 165 (5); 149 (10); 138 (21); 136 (100); 125 (20); 109 (24); 108 (11); 95 (18); 83 (19); 82 (29); 81 (29); 80 (38); 79 (22); 67 (21); 57 (74); 55 (21); 43 (22); 41 (24).

3^(rd) Major Isomers:

¹H-NMR (200 MHz, CDCl₃): δ (ppm) 0.84 (s, 9H); 0.90-1.85 (m, 7H); 1.19 (d, 3H, J=6.3 Hz); 1.32 (d, 3H, J=5.1 Hz); 1.96 (m, 1H); 3.15 (ddd, 1H, J=4.1 Hz, J=9.8 Hz, J=11.2 Hz); 3.38 (dt, 1H, J=6.3 Hz, J=9.7 Hz); 4.78 (q, 1H, J=5.1 Hz).

¹³C-NMR (50 MHz, CDCl₃, selected data): δ (ppm) 18.6; 21.2; 25.3; 26.5; 27.8; 31.6; 32.3; 46.7; 47.0; 77.1; 80.6; 98.4.

MS [e/m (%)]: idem 1st major isomers.

1^(st) Minor Isomers:

¹H-NMR (200 MHz, CDCl₃, selected data): δ (ppm) 0.83 (s, 9H); 1.24 (d, 1H, J=7.0 Hz); 1.26 (d, 3H, J=5.1 Hz); 1.96 (m, 1H); 3.47 (dt, 1H, J=4.4 Hz, J=10.7 Hz); 4.07 (dq, 1H, J=7.0 Hz, J=12.8 Hz); 5.03 (q, 1H, J=5.1 Hz).

¹³C-NMR (50 MHz, CDCl₃): δ (ppm) 13.0; 21.3; 25.3; 27.4; 27.5; 32.1; 32.2; 43.2; 47.5; 72.0; 74.2; 91.1.

MS [e/m (%)]: idem 1st major isomers.

2^(nd) Minor Isomers:

¹H-NMR (200 MHz, CDCl₃, selected data): δ (ppm) 0.83 (s, 9H); 3.16 (m, 1H); 3.44 (m, 1H); 4.69 (q, 1H, J=5.1 Hz).

¹³C-NMR (50 MHz, CDCl₃, selected data): δ (ppm) 18.0; 20.2; 25.6; 27.6; 32.0; 41.1; 47.1; 75.2; 75.7; 98.6.

MS [e/m (%)]; 211 (85); 165 (24); 149 (8); 138 (19); 125 (9); 109 (72); 108 (27); 95 (40); 83 (34); 82 (32); 81 (28); 80 (30); 79 (24); 67 (25); 57 (100); 55 (29); 43 (26); 41 (27).

Example 38 Preparation of 6-tert-butyl-4-ethyl-2-isopropyl-hexahydro-benzo[1,3]dioxine (I′bg)

Compound I′bg is obtained as a pale yellow oil in 21% yield, according to Example 23, from diol V′ b (17.83 g, 0.08 mol, obtained in Example 19), isobutyraldehyde (7.19 g, 0.1 mol) and cyclohexane (40 mL). It consists in a mixture of 5 isomers with 2 major isomers (76%) as cis/trans enantiomers in a 63:37 ratio.

Bp: 88° C./0.7 torr

Olfactory profile: herbaceous, camomile, woody.

Major Cis-Isomers:

¹H-NMR (200 MHz, CDCl₃): δ (ppm) 0.84 (s, 9H); 0.87-1.00 (m, 3H); 0.92 (d, 6H, J=7.0 Hz); 1.01-1.70 (m, 9H); 1.77 (m, 1H); 1.19 (m, 1H); 3.42 (ddd, 11-1, J=1.6 Hz, J=6.1 Hz, J=7.7 Hz); 3.64 (m, 1H); 4.28 (d, 1H, J=4.4 Hz).

¹³C-NMR (50 MHz, CDCl₃): δ (ppm) 9.9; 16.7; 17.1; 20.4; 21.4; 24.7; 27.5; 32.1; 32.5; 32.8; 38.6; 47.0; 74.5; 81.2; 104.9.

MS [e/m (%)]: 267 (M⁺, 6); 225 (62); 179 (53); 163 (4); 138 (33); 136 (1); 123 (63); 109 (45); 95 (27); 83 (19); 82 (28); 81 (30); 80 (47); 79 (19); 67 (22); 57 (100); 55 (18); 43 (18); 41 (27).

Major Trans-Isomers:

¹H-NMR (200 MHz, CDCl₃, selected data): δ (ppm) 0.85 (s, 9H); 0.91 (d, 6H, J=8.7 Hz); 3.42 (m, 1H); 3.75 (m, 1H); 4.22 (d, 1H, J=4.5 Hz).

¹³C-NMR (50 MHz, CDCl₃, selected data): δ (ppm) 9.9; 16.8; 17.1; 19.0; 24.8; 28.0; 29.5; 32.4; 32.7; 33.3; 47.0; 75.4; 81.0; 104.8.

MS [e/m (%)]: 267 (M⁺, 3); 225 (23); 179 (49); 163 (7); 138 (25); 136 (49); 123 (66); 109 (42); 95 (27); 83 (20); 82 (27); 81 (29); 80 (42); 79 (22); 67 (23); 57 (100); 55 (20); 43 (19); 41 (29).

1^(st) Minor Isomers:

¹H-NMR (200 MHz, CDCl₃, selected data): δ (ppm) 0.83 (s, 9H); 0.93 (d, 6H, J=6.8 Hz); 3.09 (m, 2H); 4.23 (d, 1H, J=5.6 Hz).

¹³C-NMR (50 MHz, CDCl₃, selected data): δ (ppm) 9.5; 17.2; 17.6; 25.1; 25.2; 26.3; 27.6; 31.7; 32.8; 44.9; 47.1; 80.6; 81.9; 105.4.

MS [elm (%)]: idem major cis isomers.

2^(nd) Minor Isomers:

¹H-NMR (200 MHz, CDCl₃, selected data): δ (ppm) 4.50 (d, 1H, J=4.2 Hz).

MS [e/m (%)]: idem major cis isomers.

3^(rd) Minor Isomers:

¹H-NMR (200 MHz, CDCl₃, selected data): δ (ppm) 4.41 (d, 1H, J=5.6 Hz).

MS [e/m (%)]: idem major cis isomers.

Example 39 Preparation of 6-tert-butyl-2-methyl-4-phenyl-hexahydro-benzo [1,3]dioxine (I′ca)

Compound I′ca is obtained as white crystals in 21% yield, according to Example 23, from diol V′c (11.55 g, 0.04 mol, obtained in Example 20), acetaldehyde (3.87 g, 0.09 mol) and cyclohexane (20 mL). It consists in a mixture of 3 isomers with 2 major isomers (77%) as cis isomers in a 56:44 ratio. The crude product was purified by column chromatography on SiO₂ (AcOEt/Hexane (5:95)) The cis isomers were obtained as white crystals, whereas the minor trans isomer was obtained as a colourless oil.

Olfactory profile: green, chemicals.

Major Cis-Isomers:

¹H-NMR (200 MHz, CDCl₃): δ (ppm) 0.73 (s, 9H); 0.80-1.80 (m, 7H); 1.46 (d, 3H, J=5.1 Hz); 2.08 (m, 1H); 3.96 (m, 1H); 4.84 (m, 1H); 4.93 (m, 1H); 7.29 (m, 5H).

¹³C-NMR (50 MHz, CDCl₃): δ (ppm) 20.7; 21.2; 21.4; 27.4; 32.1; 32.5; 40.8; 47.1; 74.9; 81.1; 99.1; 125.3; 126.8; 127.9; 140.0.

MS [e/m (%)]:287 (M⁺, 1); 229 (2); 151 (27); 138 (20); 107 (100); 80 (24); 77 (7); 57 (30); 51 (1); 39 (2).

Minor Cis-Isomers:

¹H-NMR (200 MHz, CDCl₃, selected data): δ (ppm) 0.71 (s, 9H); 1.45 (d, 3H, J=5.1 Hz); 4.08 (m, 1H).

¹³C-NMR (50 MHz, CDCl₃): δ (ppm) 19.1; 20; 21.2; 27.9; 29.3; 33.4; 35.6; 41.1; 75.4; 80.3; 98.7; 125.1; 126.7; 127.9; 140.3.

MS [e/m (%)]: idem cis-isomers.

Minor Trans-Isomers:

¹H-NMR (200 MHz, CDCl₃): δ (ppm) 0.74 (s, 9H); 0.80-1.75 (m, 6H); 1.42 (d, 3H, J=5.1 Hz); 1.76-1.95 (m, 1H); 2.03 (m, 1H); 3.37 (ddd, 1H, J=4.2 Hz, J=9.7 Hz, J=11.2 Hz); 4.24 (d, 1H, J=9.9 Hz); 4.98 (q, 1H, J=5.1 Hz); 7.31 (m, 5H).

¹³C-NMR (50 MHz, CDCl₃): δ (ppm) 21.3; 25.4; 26.4; 27.5; 31.7; 32.3; 46.3; 46.8; 80.3; 84.4; 99.1; 127.3; 128.0; 128.3; 139.4.

MS [e/m (%)]: idem major cis isomers.

Example 40 Preparation of 2,4,6,6-tetra-methyl-hexahydro-benzo[1,3]dioxine (I″aa)

Compound I″aa is obtained as a colourless oil in 58% yield, according to Example 23, from diol V″a (74.08 g, 0.43 mol, obtained in Example 21), acetaldehyde (61.95 g, 0.86 mol) and cyclohexane (180 mL). It consists in a mixture of 4 isomers with 2 major isomers (75%) as cis/trans enantiomers in a 55:45 ratio.

Bp: 52° C./1.1 torr

Olfactory profile: Aromatic, woody, powerful.

Major Cis-Isomers:

¹H-NMR (200 MHz, CDCl₃): δ (ppm) 0.86 (s, 3H); 0.94 (s, 3H); 0.95-1.65 (m, 6H); 1.11 (d, 3H, J=6.6 Hz); 1.32 (d, 3H, J=5.1 Hz); 1.72 (m, 1H); 3.72 (m, 1H); 3.82 (dq, 1H, J=2.4 Hz, J=6.6 Hz); 4.72 (q, 1H, J=5.1 Hz).

¹³C-NMR (50 MHz, CDCl₃): δ (ppm) 17.8; 21.2; 24.2; 27.6; 29.9; 32.1; 33.0; 33.2; 35.4; 74.7; 75.3; 98.7.

MS [e/m (%)]: 197 (M⁺, 4); 183 (8); 155 (2); 137 (31); 110 (100); 95 (67); 89 (22); 81 (63); 69 (11); 55 (16); 43 (20).

Major Trans-Isomers:

¹H-NMR (200 MHz, CDCl₃, selected data): δ (ppm) 0.91 (s, 3H); 0.94 (s, 3H); 1.16 (d, 3H, J=6.3 Hz); 1.33 (d, 3H, J=5.1 Hz); 3.15 (ddd, 1H, J=4.6 Hz, J=9.7 Hz, J=10.9 Hz); 3.35 (dq, 1H, J=6.3 Hz, J=9.3 Hz); 4.78 (q, 1H, J=5.1 Hz).

¹³C-NMR (50 MHz, CDCl₃): δ (ppm) 18.5; 21.2; 25.2; 27.7; 30.7; 32.7; 37.3; 38.9; 42.6; 77.3; 81.1; 98.5.

MS [e/m (%)]: 197 (M⁺, 15); 183 (95); 155 (3); 137 (57); 110 (95); 95 (97); 81 (100); 69 (21); 55 (28); 43 (33); 41 (23).

1^(st) Minor Isomers:

MS [elm (%)]:197 (M⁺, 11); 183 (100); 155 (8); 137 (68); 110 (42); 95 (68); 81 (77); 69 (19); 55 (24); 43 (28); 41 (19).

Example 41 Preparation of 4,6,6-trimethyl-2-((E)-propenyl)-hexahydro-benzo[1,3]dioxine (I″ac)

Compound I″ac is obtained as a yellow oil in 56% yield, according to Example 23, from diol V″a (31.01 g, 0.18 mol, obtained in Example 21), crotonaldehyde (14.72 g, 0.21 mol) and cyclohexane (80 mL). It consists in a mixture of 8 isomers with 2 major isomers (76%) as cis/trans enantiomers in a 55:45 ratio.

Bp: 80° C./0.8 torr

Olfactory profile: herbal, minty, fruity

Major Cis-Isomers:

¹H-NMR (200 MHz, CDCl₃): δ (ppm) 0.96 (s, 6H); 1.00-1.65 (m, 6H); 1.19 (d, 3H, J=9.0 Hz); 1.17-1.85 (m, 1H); 1.71 (d, 3H, J=1.3 Hz); 3.23 (ddd, 1H, J=4.6 Hz, J=10.0 Hz, J=10.7 Hz); 3.44 (dq, 1H, J=6.1 Hz, J=9.0 Hz); 5.04 (d, 1H, J=5.6 Hz); 5.60 (m, 1H); 5.93 (m, 1H).

¹³C-NMR (50 MHz, CDCl₃): δ (ppm) 17.7; 25.2; 27.6; 30.7; 32.0; 32.7; 38.9; 42.7; 74.8; 75.4; 100.7; 128.3; 130.7.

MS [e/m (%)]: 223 (M⁺, 16); 210 (8); 209 (60); 183 (4); 137(44); 99 (14); 95 (59); 81 (80); 71 (100); 69 (42); 55 (32); 43 (22); 41 (30).

Major Trans-Isomers:

¹H-NMR (200 MHz, CDCl₃, selected data): δ (ppm) 0.88 (s, 3H); 0.93 (s, 3H); 1.16 (d, 3H, J=8.9 Hz); 1.74 (d, 3H, J=1.4 Hz); 3.81 (m, 1H); 3.89 (m, 1H); 4.97 (d, 1H, J=6.0 Hz).

¹³C-NMR (50 MHz, CDCl₃): δ (ppm) 17.8; 24.2; 27.7; 29.8; 32.9; 33.1; 35.5; 37.3; 77.4; 81.1; 101.2; 128.6; 130.8.

MS [e/m (%)]: idem cis-isomers.

1^(st) Minor Isomers:

¹³C-NMR (50 MHz, CDCl₃, selected data): δ (ppm) 96.9; 127.7; 129.8.

MS [e/m (%)]: idem cis-isomers.

2^(nd) Minor Isomers:

¹³C-NMR (50 MHz, CDCl₃, selected data): δ (ppm) 97.1; 127.9; 129.9.

MS [e/m (%)]: idem cis-isomers.

Other Minor Isomers:

MS [e/m (%)]: 210 (12); 209 (92); 137 (100); 127 (9); 99 (1); 95 (15); 81 (12); 71 (4); 69 (7); 55 (19); 43 (8); 41 (8).

Example 42 Preparation of 4-ethyl-2-isopropyl-6,6-dimethyl-hexahydro-benzo [1,3]dioxine (I″bg)

Compound I″bg is obtained as a colourless oil in 31% yield, according to Example 23, from diol V″b (29.81 g, 0.16 mol, obtained in Example 22), isobutyraldehyde (23.05 g, 0.32 mol) and cyclohexane (70 mL). It consists in a mixture of 4 isomers with 2 major isomers (74%) as cis/trans enantiomers in a 60:40 ratio.

Bp: 106° C./5.9 torr

Olfactory profile: herbaceous

Major Cis-Isomers:

¹H-NMR (200 MHz, CDCl₃): δ (ppm) 0.55-1.00 (m, 15H); 1.01-1.67 (m, 8H); 1.68-1.90 (m, 2H); 3.44 (ddd, 1H, J=4.0 Hz, J=7.4 Hz, J=10.0 Hz); 3.66 (m, 1H); 4.27 (d, 1H, J=4.6 Hz).

¹³C-NMR (50 MHz, CDCl₃): δ (ppm) 9.8; 17.3; 24.2; 24.6; 27.8; 29.9; 32.4; 32.9; 33.3; 34.1; 37.3; 69.1; 80.9; 105.0.

MS [elm (%)]: 239 (M⁺, 4); 197 (34); 151 (100); 139 (1); 110 (70); 109 (25); 95 (69); 81 (45); 69 (17); 55 (15); 43 (18); 41 (21).

Major Trans-Isomers:

¹H-NMR (200 MHz, CDCl₃, selected data): δ (ppm) 3.10 (m, 1H); 3.44 (m, 1H); 4.41 (d, 1H, J=5.7 Hz).

¹³C-NMR (50 MHz, CDCl₃): δ (ppm) 10.0; 18.5; 24.6; 28.3; 30.9; 33.2; 39.4; 74.5; 77.2; 97.7.

MS [e/m (%)]: 239 (M⁺, 5); 197 (69); 151 (68); 139 (26); 110 (14); 109 (27); 95 (100); 81 (44); 69 (27); 55 (24); 43 (23); 41 (24).

1^(st) Minor Isomers:

¹H-NMR (200 MHz, CDCl₃, selected data): δ (ppm) 4.24 (d, 1H, J=6.0 Hz).

¹³C-NMR (50 MHz, CDCl₃, selected data): δ (ppm) 105.6.

MS [e/m (%)]: 239 (M⁺, 5); 197 (54); 151 (41); 139 (3); 110 (48); 109 (17); 95 (100); 81 (53); 69 (20); 55 (19); 43 (18); 41 (21).

2^(nd) Minor Isomers:

¹H-NMR (200 MHz, CDCl₃, selected data): δ (ppm) 4.48 (d, 1H, J=4.7 Hz).

¹³C-NMR (50 MHz, CDCl₃, selected data): δ (ppm) 97.5.

MS [e/m (%)]: 239 (M⁺, 4); 197 (65); 151 (100); 139 (22); 110 (12); 109 (26); 95 (63); 81 (29); 69 (24); 55 (20); 43 (20); 41 (19).

Example 43 Fragrance Composition Comprising the Compound Obtained in Example 28

A green woody fougere composition was prepared from the following ingredients:

Ingredients Composition A Composition B Adoxal ® 10% in DPG. 3 3 Allyl amyl glycolate 15 15 Basilic Indes ess. 3 3 Bergamote 100 100 Bouleau feuilles 5 5 Calone 1951 ® 10% in DPG 10 10 Cedramber ® 60 60 Cedre feuilles ess. 5 5 Cinnamique 10% in DPG 5 5 Citron 50 50 Citronellol pur 10 10 Corps lrg 0201 10% in DPG 40 40 Coumarine 10% in DPG 150 150 Dihydromyrcenol 90 90 Eugenol rect. VMF 10 10 Floralozone ® 10% in DPG 15 15 Folione ® 10% in DPG 1 1 Geranium chine ess. 5 5 Helional ® 15 15 cis-3-Hexenol 10% in DPG 10 10 Ionone beta 15 15 Lavandin grosso ess. 10 10 Linalol 25 25 Linalyle acetate 50 50 Mazarine ® 5 5 Melonal ® 10% in DPG 5 5 Methyl dihydrojasmonate 50 50 cis-6-Nonenol 1% in DPG 5 5 Octahydro tetramethyl acetonaphtone 133 133 Orcanox ® 1 1 Patchouly ess. 15 15 Quinoleine isobutyl 10% in DPG 5 5 Sandalore ® 20 20 Styrallyle acetate 5 5 Verdox ® 50% in DPG 54 54 2-Ethyl-4-methylhexahydro-4H- — 10 benzo[d][1,3]dioxine (Example 28) DPG 100 90 TOTAL 1000 1000

Evaluated at usual dilution in alcohol, composition A was described as very aromatic, with a tarragon note and a cyste-moss dry-down note whereas composition B (containing 2-ethyl-4-methylhexahydro-4H-benzo[d][1,3]dioxine) has a fresher note (hesperidic, grapefruit, with a slight sulphur undertone) and marine facets giving a more modern impact to the fragrance.

Evaluated at usual dilution in a shower gel base, compositions A and B show no real difference in the fragrance perception, however adding 2-ethyl-4-methylhexahydro-4H-benzo[d][1,3]dioxine to the composition brings more power to the note.

Example 44 Fragrance Composition Comprising the Compound Obtained in Example 28

A floral hesperidic watery composition was prepared from the following ingredients:

Ingredients Composition A Composition B Allyl Cyclohexylpropionate 1 1 Ambrettolide VMF 10 10 Benzyl Salicylate 50% in DPG 30 30 Bourgeonal ® 3 3 Calone 1951 ® 10% in DPG 12 12 Citron 104 104 Citronellyl acetate 2 2 Corps LRG 0201 10% in DPG 10 10 Methylpamplemousse 10 10 Cyclamen Aldehyde Extra ® 1 1 Cyclemone A ® 10% in DPG 50 50 Dihydromyrcenol 10 10 Ethyl Linalol 25 25 Floralozone ® 1 1 Florol ® 35 35 Gamma Decalactone 10% in DPG 8 8 Geraniol 10 10 Hexalon ® 3 3 cis-3-Hexenol 10% in DPG 50 50 cis-3-Hexenyl Acetate 10% in DPG 3 3 Hexylcinnamic aldehyde 20 20 Indol 10% in DPG 1 1 Ionone Beta 10 10 Lemarome ® 2 2 Liffarome ® 10% in DPG 6 6 Linalol 35 35 Linalyl Acetate 60 60 Melonal ® 10% in DPG 4 4 Methyl dihydrojasmonate 142 142 Octahydro tetramethyl acetonaphtone 35 35 Orange Bresil val. Ess. 80 80 Patchouly Ess. 4 4 Styrallyl acetate 2 2 Triplal ® 10% in DPG 15 15 Vanilline 10% in DPG 4 4 Verdox ® 50% in DPG 2 2 DPG 200 195 2-Ethyl-4-methylhexahydro-4H- — 5 benzo[d][1,3]dioxine (Example 28) TOTAL 800 800

These two compositions were used in a shower gel base and in alcohol at usual dilutions, known from the person of the art, and the samples containing the compound 2-ethyl-4-methylhexahydro-4H-benzo[d][1,3]dioxine showed a fresher lemon zest note.

In alcohol, composition B was also described as having green acidulous facets with a more floral indolic middle note, imparting a nicer and less “technique” impact to the fragrance.

Example 45 Fragrance Composition Comprising the Compound Obtained in Example 27

A wisteria accord was prepared from the following ingredients:

Ingredients Composition A Composition B Ambrettolide 20 20 Anisic aldehyde 20 20 Benzyl acetate 40 40 Benzylsalicylate 125 125 Cinnamyl acetate 50 50 DPG 10 — Geraniol 200 200 Heliotropine 50 50 Hydroxycitronellal 120 120 Isobutyl phenylacetate 50 50 Jasmine Absopop ™ 10 10 Methyl phenylacetate 5 5 Mimosa Inde abs. 20 20 Oranger Absopop ™ 10 10 Phenylethyl alcohol 60 60 Terpineol 100 100 Ylang-Ylang ess. extra 60 60 2-Benzyl-4-methyl-hexahydro- — 10 benzo[1,3]dioxine (Example 27) TOTAL 950 950

Adding 2-benzyl-4-methyl-hexahydro-benzo[1,3]dioxine to Composition A (Composition B) brings a more floral, honey-like and natural aspect to the wisteria accord, giving a rounder, sugary facet, with some lily-of-the-valley undertone.

Example 46 Fragrance Composition Containing the Derivative Obtained in Example 27

A rose accord was prepared from the following ingredients:

Ingredients Composition A Composition B Aldehyde C11 lenique, 10% DPG 7 7 Bacdanol ® 4 4 Citronellol 240 240 Citronellyl acetate 3 3 DPG 10 — Eugenol 3 3 Geraniol 30 30 Lilial ® 15 15 Methyl phenylacetate 6 6 Methylionantheme 15 15 Phenyl oxide 6 6 Phenylacetic aldehyde dimethyl acetal 5 5 Phenylethyl acetate 6 6 Phenylethyl alcohol 420 420 Rosafix ® 15 15 Triplal ® 5 5 2-Benzyl-4-methyl-hexahydro- — 10 benzo[1,3]dioxine (Example 27) TOTAL 790 790

Adding 2-benzyl-4-methyl-hexahydro-benzo[1,3]dioxine to Composition A (Composition B) gives a more natural and green aspect to the rose accord and adds sweet, powdery facets.

Example 47 Fragrance Composition Comprising the Compound Obtained in Example 27

A mimosa accord was prepared from the following ingredients:

Ingredients Composition A Composition B Anisic aldehyde 130 130 DPG 485 475 Heliotropine 15 15 Hexyl cinnamic aldehyde 370 370 2-Benzyl-4-methyl-hexahydro- — 10 benzo[1,3]dioxine (Example 27) TOTAL 1000 1000

Adding 2-benzyl-4-methyl-hexahydro-benzo[1,3]dioxine to Composition A (Composition B) really impacts the fragrance to a nice mimosa note, with powdery and green aspects.

Example 48 Fragrance Composition Comprising the Compound Obtained in Example 27

A nenuphar accord was prepared from the following ingredients:

Ingredients Composition A Composition B Benzyl acetate 360 360 Beta-Ionone 28 28 Canthoxal 4 4 Dihydromyrcenol 90 90 DPG 10 — Ethyl phtalate 52 52 EThyl vanillin 2 2 Eugenol 8 8 Gamma-decalactone 4 4 Geraniol 15 15 Helional 8 8 Hexyl acetate 10 10 Hexyl cinnamic aldehyde 20 20 Indol 2 2 Lauric aldehyde 2 2 Linalol 160 160 Melonal 2 2 Methyl dihydro jasmonate 120 120 Musc T 30 30 Phenyl ethyl alcohol 50 50 Propyl gaiacol 8 8 Triplal 1 1 2-Benzyl-4-methyl-hexahydro- — 10 benzo[1,3]dioxine (Example 27) TOTAL 790 790

Adding 2-benzyl-4-methyl-hexahydro-benzo[1,3]dioxine to Composition A (Composition B) gives a more natural and sweet water-lily note, with a slight jasminic facet. 

1. A compound of formula:

wherein: R³ and R⁴ are independently a hydrogen atom, a C1-C6 alkyl group or a C2-C6 alkenyl group, R⁵ is a C1-C6 alkyl group, a C2-C6 alkenyl group or a (CH₂)₀₋₂-aryl group, R⁶ is a C1-C6 alkyl group, a C2-C6 alkenyl group, a (CH₂)₀₋₂-aryl group or a C5-C6 cycloalkyl or cycloalkenyl group, and R⁷ is a hydrogen atom, a C1-C6 alkyl group or a C2-C6 alkenyl group; or R³, R⁴ and R⁵ are as above defined, and R⁶ and R⁷ together with the carbon atom to which they are attached form a C5-C6 cycloalkyl or cycloalkenyl group; with the proviso that said compound is not: 2,2-dimethyl-4-ethylhexahydrobenzo[1,3]dioxine 2,2-dimethyl-4-n-penthylhexahydrobenzo[1,3]dioxine 2,2-dimethyl-4-phenylhexahydrobenzo[1,3]dioxine 2,4-dimethylhexahydrobenzo[1,3]dioxine 2,4-diphenylhexahydrobenzo[1,3]dioxine 4-ethyl-2-methylhexahydrobenzo[1,3]dioxine 4-methyl-2-phenylhexahydrobenzo[1,3]dioxine 2,2,4-trimethylhexahydrobenzo[1,3]dioxine.
 2. The compound according to claim 1, wherein: R³ and R⁴ are independently selected from the group consisting of a hydrogen atom, methyl, ethyl, i-propyl, i-butyl and t-butyl, R⁵ is selected from the group consisting of methyl, ethyl, i-propyl, i-butyl, t-butyl, n-pentyl, 1-propen-1-yl, allyl, vinyl and phenyl, R⁶ is selected from the group consisting of methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, n-pentyl, 1-propen-1-yl, phenyl, benzyl and 2,4-dimethylcyclohexen-3-yl, and R⁷ is selected from the group consisting of a hydrogen atom, methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, n-pentyl and 1-propen-1-yl.
 3. The compound according to claim 1, wherein: R³ and R⁴ are hydrogen atoms, R⁵ is selected from the group consisting of methyl, ethyl, 1-butyl and phenyl, R⁶ is selected from the group consisting of methyl, ethyl, i-propyl, phenyl, benzyl and 2,4-dimethylcyclohexen-3-yl, and R⁷ is selected from the group consisting of a hydrogen atom, methyl and n-butyl.
 4. The compound according to claim 3, wherein: R³, R⁴ and R⁷ are hydrogen atoms, and R⁵ is methyl, and R⁶ is ethyl or benzyl.
 5. The compound according to claim 1, wherein: R³ and R⁷ are hydrogen atoms, R⁴ is t-butyl, R⁵ is methyl, ethyl or phenyl, and R⁶ is methyl or i-propyl.
 6. The compound according to claim 1, wherein: R³ and R⁴ are methyls, R⁵ is methyl or ethyl, R⁶ is selected from the group consisting of methyl, i-propyl and 1-propen-1-yl, and R⁷ is a hydrogen atom.
 7. The compound according to claim 1, selected in from the group consisting of: 2,4-dimethyl-hexahydro-benzo[1,3]dioxine 4-methyl-2-pentyl-hexahydro-benzo[1,3]dioxine 4-methyl-2-propenyl-hexahydro-benzo[1,3]dioxine 4-methyl-2-phenyl-hexahydro-benzo[1,3]dioxine 2-benzyl-4-methyl-hexahydro-benzo[1,3]dioxine 2-ethyl-4-methylhexahydro-4H-benzo[d][1,3]dioxine 2,2,4-trimethylhexahydro-4H-benzo[d][1,3]dioxine 2-butyl-2,4-dimethylhexahydro-4H-benzo[d][1,3]dioxine 4-methylhexahydro-4H-spiro[benzo[d][1,3]dioxine-2,1′-cyclopentane] 2-(2,4-dimethylcyclohex-3-enyl)-4-methylhexahydro-4H-benzo[d][1,3]dioxine 2-(2,4-dimethylcyclohex-3-enyl)-4-methylhexahydro-4H-benzo[d][1,3]dioxine 4-ethyl-2-isopropyl-hexahydro-benzo[1,3]dioxine 2-methyl-4-phenyl-hexahydro-benzo[1,3]dioxine 4-isobutyl-2-methylhexahydro-4H-benzo[d][1,3]dioxine 6-tert-butyl-2,4-dimethyl-hexahydro-benzo[1,3]dioxine 6-tert-butyl-4-ethyl-2-isopropyl-hexahydro-benzo[1,3]dioxine 6-tert-butyl-2-methyl-4-phenyl-hexahydro-benzo[1,3]dioxine 2,4,6,6-tetra-methyl-hexahydro-benzo[1,3]dioxine 4,6,6-trimethyl-2-((E)-propenyl)hexahydro-benzo[1,3]dioxine 4-ethyl-2-isopropyl-6,6-dimethyl-hexahydro-benzo[1,3]dioxine.
 8. A fragrant composition comprising, as a fragrant agent, at least one compound of formula:

wherein: R³ and R⁴ are independently a hydrogen atom, a C1-C6 alkyl group or a C2-C6 alkenyl group, R⁵ is a C1-C6 alkyl group, a C2-C6 alkenyl group or a (CH₂)₀₋₂-aryl group, R⁶ is a C1-C6 alkyl group, a C2-C6 alkenyl group, a (CH₂)₀₋₂-aryl group or a C5-C6 cycloalkyl or cycloalkenyl group, and R⁷ is a hydrogen atom, a C1-C6 alkyl group or a C2-C6 alkenyl group; or R³, R⁴ and R⁵ are as above defined, and R⁶ and R⁷ together with the carbon atom to which they are attached form a C5-C6 cycloalkyl or cycloalkenyl group.
 9. The composition according to claim 8, comprising, as a fragrant agent, at least one compound with the proviso that said compound is not: 2,2-dimethyl-4-ethylhexahydrobenzo[1,3]dioxine 2,2-dimethyl-4-n-penthylhexahydrobenzo[1,3]dioxine 2,2-dimethyl-4-phenylhexahydrobenzo[1,3]dioxine 2,4-dimethylhexahydrobenzo[1,3]dioxine 2,4-diphenylhexahydrobenzo[1,3]dioxine 4-ethyl-2-methylhexahydrobenzo[1,3]dioxine 4-methyl-2-phenylhexahydrobenzo[1,3]dioxine 2,2,4-trimethylhexahydrobenzo[1,3]dioxine.
 10. The composition according to claim 8, selected from the group consisting of perfumed bases, concentrates, fragrances, perfumes and similar products.
 11. The composition according to claim 8, as a masking agent of odours.
 12. The composition according to claim 8, comprising, as a fragrant agent, at least one compound wherein: R³ and R⁴ are independently selected from the group consisting of a hydrogen atom, methyl, ethyl, i-propyl, i-butyl and t-butyl, R⁵ is selected from the group consisting of methyl, ethyl, i-propyl, i-butyl, t-butyl, n-pentyl, 1-propen-1-yl, allyl, vinyl and phenyl, R⁶ is selected from the group consisting of methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, n-pentyl, 1-propen-1-yl, phenyl, benzyl and 2,4-dimethylcyclohexen-3-yl, and R⁷ is selected from the group consisting of a hydrogen atom, methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, n-pentyl and 1-propen-1-yl.
 13. The composition according to claim 8, comprising, as a fragrant agent, at least one compound wherein: R³ and R⁴ are hydrogen atoms, R⁵ is selected from the group consisting of methyl, ethyl, i-butyl and phenyl, R⁶ is selected from the group consisting of methyl, ethyl, i-propyl, phenyl, benzyl and 2,4-dimethylcyclohexen-3-yl, and R⁷ is selected from the group consisting of a hydrogen atom, methyl and n-butyl.
 14. The composition according to claim 8, comprising, as a fragrant agent, at least one compound wherein: R³, R⁴ and R⁷ are hydrogen atoms, and R⁵ is methyl, and R⁶ is ethyl or benzyl.
 15. The composition according to claim 8, comprising, as a fragrant agent, at least one compound wherein: R³ and R⁷ are hydrogen atoms, R⁴ is t-butyl, R⁵ is methyl, ethyl or phenyl, and R⁶ is methyl or i-propyl.
 16. The composition according to claim 8, comprising, as a fragrant agent, at least one compound wherein: R³ and R⁴ are methyls, R⁵ is methyl or ethyl, R⁶ is selected from the group consisting of methyl, i-propyl and 1-propen-1-yl, and R⁷ is a hydrogen atom.
 17. The composition according to claim 8, comprising, as a fragrant agent, at least one compound, selected in from the group consisting of: 2,4-dimethyl-hexahydro-benzo[1,3]dioxine 4-methyl-2-pentyl-hexahydro-benzo[1,3]dioxine 4-methyl-2-propenyl-hexahydro-benzo[1,3]dioxine 4-methyl-2-phenyl-hexahydro-benzo[1,3]dioxine 2-benzyl-4-methyl-hexahydro-benzo[1,3]dioxine 2-ethyl-4-methylhexahydro-4H-benzo[d][1,3]dioxine 2,2,4-trimethylhexahydro-4H-benzo[d][1,3]dioxine 2-butyl-2,4-dimethylhexahydro-4H-benzo[d][1,3]dioxine 4-methylhexahydro-4H-spiro[benzo[d][1,3]dioxine-2,1′-cyclopentane] 2-(2,4-dimethylcyclohex-3-enyl)-4-methylhexahydro-4H-benzo[d][1,3]dioxine 2-(2,4-dimethylcyclohex-3-enyl)-4-methylhexahydro-4H-benzo[d][1,3]dioxine 4-ethyl-2-isopropyl-hexahydro-benzo[1,3]dioxine 2-methyl-4-phenyl-hexahydro-benzo[1,3]dioxine 4-isobutyl-2-methylhexahydro-4H-benzo[d][1,3]dioxine 6-tert-butyl-2,4-dimethyl-hexahydro-benzo[1,3]dioxine 6-tert-butyl-4-ethyl-2-isopropyl-hexahydro-benzo[1,3]dioxine 6-tert-butyl-2-methyl-4-phenyl-hexahydro-benzo[1,3]dioxine 2,4,6,6-tetra-methyl-hexahydro-benzo[1,3]dioxine 4,6,6-trimethyl-2-((E)-propenyl)-hexahydro-benzo[1,3]dioxine 4-ethyl-2-isopropyl-6,6-dimethyl-hexahydro-benzo[1,3]dioxine. 